# Update Chapter

POST https://api.elevenlabs.io/v1/studio/projects//chapters/
Content-Type: application/json

Updates a chapter.

Reference: https://elevenlabs.io/docs/api-reference/studio/update-chapter

## Servers

- `https://api.elevenlabs.io` (Production, default)
- `https://api.us.elevenlabs.io` (Production US)
- `https://api.eu.residency.elevenlabs.io` (Production EU)
- `https://api.in.residency.elevenlabs.io` (Production India)
- `https://api.sg.residency.elevenlabs.io` (Production Singapore)

## Request

### Path parameters

- `project_id` (string, required) — The ID of the project to be used. You can use the [List projects](/guides/api-reference-studio-get-projects) endpoint to list all the available projects.
- `chapter_id` (string, required) — The ID of the chapter to be used. You can use the [List project chapters](/guides/api-reference-studio-get-chapters) endpoint to list all the available chapters.

### Body (application/json)

This endpoint expects a Body\_Update\_chapter\_v1\_studio\_projects\_\_project\_id\_\_chapters\_\_chapter\_id\_\_post.

- `name` (string, optional, nullable) — The name of the chapter, used for identification only.
- `content` (ChapterContentInputModel, optional, nullable) — The chapter content to use.

## Response

### 200

Successful Response

- `chapter` (ChapterWithContentResponseModel, required)

## Errors

### 422 Unprocessable Entity Error

Validation Error

- `detail` (list of ValidationError, optional)

## Types

### ChapterContentInputModel

- `blocks` (list of ChapterContentBlockInputModel, required)

### ChapterWithContentResponseModel

- `chapter_id` (string, required) — The ID of the chapter.
- `name` (string, required) — The name of the chapter.
- `can_be_downloaded` (boolean, required) — Whether the chapter can be downloaded.
- `state` (enum, required) — The state of the chapter.
  - Allowed values: `default`, `converting`
- `content` (ChapterContentResponseModel, required)
- `last_conversion_date_unix` (integer, optional, nullable) — The last conversion date of the chapter.
- `conversion_progress` (double, optional, nullable) — The conversion progress of the chapter.
- `has_video` (boolean, optional, nullable) — Whether the chapter has a video.
- `has_visual_content` (boolean, optional, nullable) — Whether the chapter has any visual content (video, image, or text clips).
- `voice_ids` (list of string, optional, nullable) — List of voice ids used by the chapter
- `statistics` (ChapterStatisticsResponseModel, optional, nullable) — The statistics of the chapter.
- `last_conversion_error` (string, optional, nullable) — The last conversion error of the chapter.

### ValidationError

- `loc` (list of ValidationErrorLocItems, required)
- `msg` (string, required)
- `type` (string, required)

### ChapterContentBlockInputModel

- `nodes` (list of ChapterContentParagraphTtsNodeInputModel, required)
- `sub_type` (enum, optional, nullable)
  - Allowed values: `p`, `h1`, `h2`, `h3`
- `block_id` (string, optional, nullable)

### ChapterContentResponseModel

- `blocks` (list of ChapterContentBlockResponseModel, required)

### ChapterStatisticsResponseModel

- `characters_unconverted` (integer, required) — The number of unconverted characters.
- `characters_converted` (integer, required) — The number of converted characters.
- `paragraphs_converted` (integer, required) — The number of converted paragraphs.
- `paragraphs_unconverted` (integer, required) — The number of unconverted paragraphs.
- `credits_needed_to_convert` (integer, optional, nullable) — The number of credits needed to convert the remaining paragraphs.
- `voice_statistics` (list of VoiceStatisticsResponseModel, optional, nullable) — Per-voice breakdown of character counts.

### ValidationErrorLocItems

### ChapterContentParagraphTtsNodeInputModel

- `type` ("tts\_node", required)
- `text` (string, required)
- `voice_id` (string, required)

### ChapterContentBlockResponseModel

- `block_id` (string, required)
- `nodes` (list of ChapterContentBlockResponseModelNodesItems, required)

### VoiceStatisticsResponseModel

- `project_voice_ref_id` (string, required) — The project voice reference ID.
- `characters_unconverted` (integer, required) — The number of unconverted characters for this voice.
- `characters_converted` (integer, required) — The number of converted characters for this voice.
- `voice_id` (string, required, deprecated) — The voice ID.
- `credits_needed_to_convert` (integer, optional, nullable) — The number of credits needed to convert the remaining audio for this voice.

### ChapterContentBlockResponseModelNodesItems

### ChapterContentBlockTtsNodeResponseModel

- `type` ("tts\_node", required)
- `project_voice_ref_id` (string, required)
- `text` (string, required)
- `voice_id` (string, required, deprecated)

### ChapterContentBlockExtendableNodeResponseModel

Not used. Make sure you anticipate new types in the future.

- `type` ("\_other", required)

## Examples

**Request**

```json
{}
```

**Response**

```json
{
  "chapter": {
    "chapter_id": "aw1NgEzBg83R7vgmiJt6",
    "name": "Chapter 1",
    "can_be_downloaded": true,
    "state": "default",
    "content": {
      "blocks": []
    },
    "last_conversion_date_unix": 1714204800,
    "conversion_progress": 0.5,
    "statistics": {
      "characters_unconverted": 100,
      "characters_converted": 200,
      "paragraphs_converted": 5,
      "paragraphs_unconverted": 3
    }
  }
}
```

**SDK Code**

```typescript
import { ElevenLabsClient } from "@elevenlabs/elevenlabs-js";

async function main() {
    const client = new ElevenLabsClient();
    await client.studio.projects.chapters.update("21m00Tcm4TlvDq8ikWAM", "21m00Tcm4TlvDq8ikWAM", {});
}
main();

```

```python
from elevenlabs import ElevenLabs

client = ElevenLabs()

client.studio.projects.chapters.update(
    project_id="21m00Tcm4TlvDq8ikWAM",
    chapter_id="21m00Tcm4TlvDq8ikWAM",
)

```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.elevenlabs.io/v1/studio/projects/21m00Tcm4TlvDq8ikWAM/chapters/21m00Tcm4TlvDq8ikWAM"

	payload := strings.NewReader("{}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.elevenlabs.io/v1/studio/projects/21m00Tcm4TlvDq8ikWAM/chapters/21m00Tcm4TlvDq8ikWAM")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.elevenlabs.io/v1/studio/projects/21m00Tcm4TlvDq8ikWAM/chapters/21m00Tcm4TlvDq8ikWAM")
  .header("Content-Type", "application/json")
  .body("{}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.elevenlabs.io/v1/studio/projects/21m00Tcm4TlvDq8ikWAM/chapters/21m00Tcm4TlvDq8ikWAM', [
  'body' => '{}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.elevenlabs.io/v1/studio/projects/21m00Tcm4TlvDq8ikWAM/chapters/21m00Tcm4TlvDq8ikWAM");
var request = new RestRequest(Method.POST);
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Content-Type": "application/json"]
let parameters = [] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.elevenlabs.io/v1/studio/projects/21m00Tcm4TlvDq8ikWAM/chapters/21m00Tcm4TlvDq8ikWAM")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```

## Related pages

- [Administration](./administration-index.md)
- [API reference](./api-reference-index.md)
- [Changelog](./changelog-index.md)
- [ElevenAgents](./elevenagents-index.md)
- [ElevenAPI](./elevenapi-index.md)
- [ElevenCreative](./elevencreative-index.md)
- [ElevenLabs Documentation Docs](../index.md)
- [General Troubleshooting FAQ](./troubleshooting-index.md)
- [General Website FAQ](./website-index.md)
- [Help Center](./help-center-2-index.md)

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